Table 2.

Tests for interaction between baseline prognostic features and treatment

	HR (95% CI)*	p value*
Age (<70 years vs ≥70 years)	1·073 (0·772–1·491)	0·6764
ECOG performance status (0 vs 1)	1·271 (0·906–1·782)	0·1655
Alkaline phosphatase concentration (<1·5 times ULN vs ≥ 1·5 times ULN)	1·178 (0·847–1·637)	0·3304
Gleason score (≤7 vs ≥8)	0·888 (0·631–1·250)	0·4971
Lactate dehydrogenase concentration (≤2 times ULN vs >2 times ULN)	1·214 (0·789–1·870)	0·3778
Visceral metastases (no vs yes)	1·644 (1·157–2·336)	0·0056
Haemoglobin concentration (<110 g/L vs ≥110 g/L)	0·842 (0·597–1·187)	0·3257
Average daily worst bone pain intensity score (<4 vs ≥4)	1·057 (0·735–1·519)	0·7645
Log of PSA concentration	0·951 (0·845–1·071)	0·4105
Number of bone metastases (≤5 vs >5)	0·954 (0·655–1·391)	0·8077
Number of bone regions with metastases (1 vs ≥2)	1·156 (0·792–1·689)	0·4526

No adjustments were made for multiplicity. Log of prostate-specific antigen (PSA) concentration was treated as a continuous variable, whereas all other prognostic features were treated as categorical variables. ECOG=Eastern Cooperative Oncology Group. ULN=upper limit of normal. PSA=prostate-specific antigen.

^*Hazard ratios and p values are for exploratory purposes only.